Tightrope (4,4)
I believe the answer is:
high wire
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">tightrope</span>' is the definition.<br/ ><span class="explanation-format__explanation">(high wire is a kind of tightrope)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for high wire that I've seen before include "Elevated tightrope" , "Tightrope for acrobats" .)